Improved Flask Management

I have implemented a few small changes aimed at making flask management simpler and more intuitive. You can access these with the FLASK command.

- FLASK LIST will show a list of the flasks in your inventory.
- FLASK TRANSFER <flask1> TO <flask2> will transfer as much fluid from flask1 to flask2 as possible. Please note that both flasks need to be in your inventory for this to work.

Feel free to message me with concerns about the new commands or suggestions for how we might further improve flask management.